The high speeds in warp knitting frequently require technical modifications to be made along the entire production chain – especially in warp preparation. Lace production is one example of this. KARL MAYER’s modern lace raschel machines can currently reach speeds of up to 900 min-1 and are equipped for high-speed running with an active yarn delivery unit and the Positive Patternbeam Drive (PPD). The PPD electric motor system delivers the exact amount of yarn required, thus minimising stressing of the yarns during processing. However, the PPD can only realise its full potential if the yarn carriers, i.e. the pattern beams, are wound extremely precisely. All the packages on one beam axle must have exactly the same diameter. If the pattern beams also have long running lengths, the setting-up time needed to change the beams at the warp knitting machines can be reduced. Being able to produce long warping lengths and uniform package diameters was a primary requirement in developing the new PBW 130"/2 (Fig. 1) at KARL MAYER.

Designed for accuracy and operating efficiency

The new pattern beam warping machine enables packages with large widths and diameters to be produced, thus guaranteeing long running lengths. The factor that limits the width is the point at which the adjacent packages meet. The machine operator can set a width of between 25 and 220 mm, depending on how many yarns have to be wound onto a beam axle. The maximum warp length that can be selected is 100,000 m and the setting will depend on the yarn count. The maximum diameter is 140 mm. Once the limit is reached, the machine switches off to prevent over-warping. If the raschel machine, on which the pattern beam is to be subsequently processed, can handle large packages, the warping process can be continued. In this case, the switch-off point is when there is a correlation with the warping length that has been input or with the maximum possible diameter. The diameters of the packages are all exactly the same. This high level of precision guarantees a constant yarn tension across all the yarns being delivered to the knitting point, which is an important criterion when operating at fast speeds and high quality levels. In order to fully utilise the possibilities of producing perfect packages offered by the new pattern beam warping machine, the yarn tension levels must be set so that they are absolutely identical at the creel. Quality begins at the creel! When producing pattern beams, the new PBW 130"/2 operates at a speed of 10 to 400 m/min. The operator can set the most suitable speed in each case, depending on the beam quality and sensitivity of the yarns.

Also suitable for smooth yarns

The PBW 130"/2 is suitable for processing a wide range of different yarns. If very smooth yarns have to be processed, biconical packages with an angle of up to 60 guarantee a slip-free build. With this tapering shape, the edges of the yarn layers form a bevel, which prevents the upper layers from falling down. The more acute the angle selected, the narrower is the package and the greater is the loss of volume as well. A loss in output is unavoidable with biconical warping.

User friendly and accessible technology

The PBW 130"/2 scores points by having a well-thought-out, easy-to-input logistics system operated via a touchscreen monitor. The user interface is available in German, English and Chinese. To make things easier for the operators, especially when inputting data relating to the warping jobs, menu navigation is restricted to one side of the screen. Here, the operator can select the four parameters relevant to the job. The machine’s computer automatically calculates the remaining parameters in the background, such as the package ratio, return path of the traverse motion and winding ratio, and adjusts them to the best possible ratios.Since the PBW 130"/2 can simultaneously produce two pattern beams completely independently of each other on two levels, the screen is divided into two halves (Fig. 2). The processes involved in producing the two beams run completely autonomously. Only in the event of a yarn breakage is the operation stopped at both the upper and lower levels for safety reasons.